Larger lighting systems, in which numerous lamps are activated by a central control device, have the advantage, in comparison with locally activated individual lamps, that a coordinated performance of all the lights can be more easily and efficiently obtained. This means, e.g., that all of the lamps are collectively activated in a predefined time period, e.g. during normal work and business hours, and their respective brightness is adjusted such that on the whole, a homogenous lighting is obtained. Such a performance of the lights in relation to one another is desirable in public buildings or larger spaces, e.g. open-plan offices or factories, because this results in a significantly more pleasant impression.
One of the problems known with such systems is that, with regard to the light output, it is relatively simple to obtain a coordinated performance of the lamps, whereas a temporally synchronized performance of the lamps is much more difficult to achieve. The reason for this is that the lamps do not normally change their performance automatically at specific predefined points in time, but rather, a control command is issued by a single primary control device, which is received by all of the lamps, and is to be implemented accordingly. The transmission of this control command to all of the lamps of the system requires, however, more or less time, depending on the positions of the lamps. This is because normally, the original command issued by the control device does not reach all of the lamps, but instead, is repeated by some of the units in the system, thus re-issued, such that it propagates in a cascading manner over the entire system, until it has been received by all of the lamps. The receiving and resending of the control command requires some time, however, such that lamps, for example, that first receive the command after the third repetition, react significantly later than those lamps that have received the control command issued by the primary control device directly. This may then make it noticeable, for example, that following a centrally issued command to switch the lamps on, those at an increasing distance to the control device are first activated successively, which is clearly visible to an observer.
The problems described above also exist independently of whether the control commands are transmitted via a signal line or in a wireless manner, e.g. by radio or infrared radiation, because in both cases, the control command must be resent, in particular with large systems, in order to be able to propagate over the entire system. These problems are also not specific to lighting systems, but instead, also pertain to other systems that have loads in a distributed arrangement, with which it is desired that the loads react substantially simultaneously to a control command.
The present invention therefore addresses the object of avoiding the disadvantages described above in systems of loads or units in a distributed arrangement, and to optimize the temporally coordinated performance of the units after a central control command has been issued.
The object is achieved by a method for transmitting control as described herein, and also by a system of units in a distributed arrangement as described herein.